Realms
This is the first edition of Realms¸ still available at a reduced price.
A huge and rich fantasy setting developed from the FATE and FUDGE rules.
Realms has lots of advice for building realistic fantasy environments¸ and populating them with people¸ monsters and magic.
Realms has a realistic approach to sword combat and armour¸ and lots of other weapons too¸ without getting bogged down in too much detail. This leaves more space for fun stuff like magic¸ monsters and adventure.
There are lots of examples of magic items¸ fearsome monsters¸ the effects of the environment¸ realistic city life¸ and the likelihood of finding shelter in the wilderness.
And at the centre of the system is the character. Everything is built around them¸ to make the character¸ and the gaming experience as in depth¸ character centred and fun as possible.